1. Field of the Invention
The present invention relates to a printing device which can be commonly used by a plurality of users through a plurality of host devices. The present invention also relates to a host device which is connected to the printing device so that a user can use the printing device through the host device. In particular, the present invention relates to a printing device which performs print jobs in the order determined by priorities of print requests, and a host device connected with such a printing device.
2. Description of the Related Art
For example, Japanese Unexamined Patent Publications, No. 5-189174 (titled xe2x80x9cControl System of a Plurality of Print Queuesxe2x80x9d) and No. 7-129336 (titled xe2x80x9cPrinting Device and System Thereofxe2x80x9d) propose techniques in which a plurality of print requests are received, and at least one print queue is manipulated so that execution of urgent or higher priority print requests take precedence over execution of lower priority print requests. That is, according to the above techniques, when a print job is required to be urgently performed, the print job is immediately performed. In this case, no explanation is made to users on the reason for the precedence of the urgent print job, or no negotiation is conducted with other users for withdrawal of other print requests which have been made previously by other users.
On the other hand, Japanese Unexamined Patent Publications, No. 5-250112 (titled xe2x80x9cPrint Output Control Systemxe2x80x9d) proposes a technique in which completion times of print outputs in response to a plurality of print requests are informed to users when contents of a print queue are changed, while the completion times of print outputs are normally informed to the users only when the plurality of print requests are received.
However, in the printing systems where users can freely manipulate the priority, bad-mannered users may abuse the function of raising the priority for their usual print jobs in addition to the urgent print job. If the function of raising the priority is abused by the bad-mannered users, well-mannered users may suffer a loss. In particular, such an abuse may impede execution of really urgent print jobs.
An object of the present invention is to provide a printing device in which abuse of the function of raising the priority of a print job is prevented, and all of the users can use urgent print service fairly and smoothly.
Another object of the present invention is to provide a host device which enables all of the users to fairly and smoothly use urgent print service of a printing device.
According to the first aspect of the present invention, there is provided a printing device for performing printing operations requested by a plurality of print requests, in an order in which the plurality of print requests are arranged. The printing device comprises a print control unit which changes ordinal positions of said plurality of print requests in said order according to priorities of said plurality of print requests so that an ordinal position of a print request with a higher priority precedes an ordinal position of a print request with a lower priority; and an information unit which sends information on a first user or first host device to at least one of second users or second host devices other than said first user or first host device when said printing device receives from said first user or first host device a print request with a priority higher than a predetermined priority.
In the printing device according to the first aspect of the present invention, a user or host device who makes a print request with a high priority can be known by the other users. Therefore, it is possible to obtain the consent of the other users to the print request having the priority, and prevent users from easily manipulating the priority or abusing the priority manipulation.
The printing device according to the first aspect of the present invention may have one or any possible combination of the following additional features (i) to (viii).
(i) The information unit may send the information to all users registered in the printing device or all host devices connected to the printing device. In this case, the effect of preventing the abuse of the function of raising a priority is enhanced.
(ii) The information unit may send the information to at least one of third users or third host devices which made a print request the ordinal position of which was changed to a lower place by the print control unit. In this case, it is easy to call attention of the users who may have to cope with the change of the ordinal positions in the order.
(iii) The printing device according to the first aspect of the present invention may further comprise a request recording unit which records as a log print requests with priorities higher than a predetermined priority. In this case, users can confirm the times of the occurrences of priority processing, and the number of occurrences of priority processing within a predetermined period of time for each user. Therefore, abuse of the priority processing can be prevented
(iv) The information unit may send the information by electronic mail. In this case, the information can be sent to users by using the existing system, and therefore, it is not necessary to provide a further means for sending the information to the users.
(v) The information sent by the information unit may include a reason for the priority of the print request. In this case, users of requests the ordinal positions of which are preceded by the (newly received) request in the above order can confirm necessity or urgency of the (newly received) request, and the consent of the other users to the priority of the (newly received) request can be obtained more easily.
(vi) The printing device according to the first aspect of the present invention may further comprise a reason recording unit which records as a log reasons for the priorities of the print requests. In this case, the same effects as above feature (v) can be obtained.
(vii) The printing device according to the first aspect of the present invention may further comprise a prohibition unit which prohibits the printing operation of the printing unit for a print request which is not accompanied by information on a reason for the priority of the print request. In this case, it is possible to prevent users from easily raising a priority.
(viii) The printing device according to the first aspect of the present invention may further comprise a model storing unit which stores reasons for the priorities of the print requests as models for the reasons. In this case, users can share the reasons for priorities of print request. That is, users who wishes to make a new request can refer to priorities of print requests which have been set for the same reason by other users, and set a priority for the new request so as to be balanced with the priorities set by the other users. Therefore, it is more probable that users who have made requests the ordinal positions of which are preceded by the new request accept the priority of the new request.
According to the second aspect of the present invention, there is provided a host device including a priority input unit which inputs a priority of a print request; a transmitting unit which transmits the print request and the priority; and a transmission control unit which controls the transmitting unit so as to transmit a reason for the priority of the print request together with the print request and the priority, when the priority is higher than a predetermined priority.
The host device according to the second aspect of the present invention may have one possible combination of the following additional feature (ix).
(ix) The host device according to the second aspect of the present invention may further comprise a model storing unit which stores reasons for the priorities of the print requests as models for said reasons. In this case, a criterion for determining whether or not the priority is allowed to be raised becomes clearer. In addition, users can refer to and revise the above reason for the priority as needed, and easily produce a reason for a priority according to the circumstances.